SLACK-HEADED GtJLL 61 



their native coasts. The other gulls are of similar habits to the 

 common gull, but particular note may be made of the 



BLACK-HEADED GULL (Lams ridibundus), Fig. 120, as affecting the 

 farming and fisheries in the north of England, particularly Cum- 

 berland, where its food consists of vegetable and animal matter 

 considered neutral in nature. " Of 100 birds examined 40 contained 

 food which would lead the bird to be classed as ' harmful,' e.g. 

 fishes, cereals, useful insects ; 47 contained ' beneficial ' food, e.g. 

 injurious insects and mollusca, carrion, and waste animal matter ; 

 and 82 contained ' neutral ' food, e.g., earthworms, Crustacea, and 

 spiders, harmless insects and mollusca, and vegetable matter other 

 than cereals " (The Journal of the Board of Agriculture, Vol. XIV., 

 No. 7, p. in). Earthworms appear the staple food of the black- 

 headed gull in inland districts, though wire worms, leather- jackets, 

 common slugs, beetles and flies injurious, harmless, and bene- 

 ficial are taken indiscriminately. Fish is sparingly eaten, partly 

 from want of opportunity, as the black-headed gull does not readily 

 obtain fish from water more than a few inches in depth, and partly 

 from the greater ease with which other food can be procured at 

 most seasons of the year. But gulls, like most other creatures, 

 acquire new habits under abnormal increase, and then become in- 

 jurious to the farming and fishing interests. Worms and other 

 invertebrate animal food may suffice under no shortage of supply, 

 but directly there is a deficiency of this class of food the gulls be- 

 come addicted to the taking of grain (oats) and other vegetable 

 produce, and to capturing and eating fish. 



